Method of making combined abrasives and holders



Aug. 8, 1933. M. c. HUTTO 1,920,986

METHOD OF MAKING COMBINED ABRASIVES AND HOLDERS Original Filed Dec. 11,1926 Patented Au 8, 1933 UNITED STATES PATENT OFFICE METHOD OF MAKINGCOMBINED ABRASIVES AND HOLDERS Marsden 0. Butte, Detroit, Mich,assignor" to Hutto Engineering tion of Michigan Company, Inc., aCorporaher 4, 1932 This invention relates to a method of making combinedabrasives and holders for grinders of internal and external cylindricalsurfaces, and more particularly to a combined abrasive and holder ofchannel form. i

This application is a division of an application filed December 11,1926, Serial No. 154,280, patented November 20, 1928, No. 1,692,661.

The object of the invention is to provide a combined holder andabrasive'in which the abrasive member, usually in the form of a naturalor artificial stone is-supported ina channeled member or othersupporting base having associated therewith members engaged by theadjusting means of the tool of which it forms a part so that thegrinding face of the abrasive is mounted in the tool in a preciserelationship with the adjusting device. In the tool with which i thecombined abrasive and holder is used, as m shown herein, severalabrasive members are mounted in a head intended to be reciprocated androtated in the cylindrical aperture to be ground, and a feature of thisinvention relates more particularly to the holder of channel-like formin which the stone is secured by a selfhardeningmaterial, that is,flowed to place in a more or less liquid form. This material may besolder, babbitt or lead or a varnish, shellac or the like and, while thestone and holder are held in the relative final positions, the materialfor securing the stone in place is supplied thereto.

' A further feature of the invention is in the provision of a holder,preferably of sheet metal form, with which the'portions thereof adaptedas for engagement with the adjusting device of the tool are riveted inplace and the stone mounted therein by a solder or suitable material-inwhich the stone is "floated" or flowed in its final relationship withthe holder and thus fixed in pre- 10 determined correct, technicalposition, as the material hardens.

As is hereinafter more fully described it is preferable, though notabsolutely necessary, to

utilize a pair of pins each adjacent an end of the holder which, when inthe tool, fit against opposing coned members that are adjustable towardor from each other and -in order that all the holders and the faces ofall the abrasives shall lie in the same circle, it is essential thatthese cone contacting portions, which may be the pins as shown, shall beof a certain length relative to the grinding face of the stone. Thus themethod of manufacture of the abrasive and its holder as hereinafterdescribed seeks primrilytoinsureaccuracyinthemountingof 4 Claims. (01.51-278) the stone so that the face which lies longitudinally of the toolshall normally be strictly parallel with the axis thereof- Stones usedin cylinder grinders or lapping devices are usually made of compactedgranular material such as carborundum or like abrasive and subsequentlyfired. Such stones usually vary in thickness throughout their length andtherefore require dressing after the stone has been mounted in itsholder.

A feature of this invention is in providing a holder and a method ofmounting the stone therein which insures parallelism of the grindingface of the stone with the axis of the tool in which it is to be usedirrespective of variations in thickness of the stone. Thus, the surfaceof the stone is normally exactly parallel with the axis of rotation ofthe grinding head or body. d

An object of this invention therefore is to provide a holder and a stonein which the holder and the stone are held in the desired finalrelationship and a self-hardening material, flowed between the memberswhereby they automatically become fixed in the necessary relationshipand the finishing of the stone subsequent to mounting is dispensed withinasmuch as the major inaccuracies are compensated for by theself-hardening material.

These objects and the several novel features of the inventionarehereinafter more fully described and claimed, and the preferred form ofan abrasive and its carrier or holder embodying this invention are shownin the accompanying drawing in which- Figure 1 is a longitudinal sectionof a tool showing the improved abrasive and itsholder mounted therein inaccordance with this method.

Figure 2 is a perspective view of the finished holder and stone. 95

Figure 3 is a cross section, taken on line 3-3 of Fig. 2.

Figure 4 is a cross section of the holder and the stone indicating themethod of securing the stone in place therein. 10o

Figuresfi and 6 are vertical longitudinal sections, on a reduced scale,taken on the correspondingly numbered lines inFig. 4, the selfhardeningmaterial being shown between the supporting base and the stone.corresponding to 105 Fig. 3.

In the invention herein described the holder consists of a supportingbase having preferably the form of a shell or channeled member 1 which,as here shown, is preferably made of sheet metal no formed in a die andmay be provided with an Y the holder and at right the holder and theface channel member being 7 This shell or channeled member 1 preferablyhas a U shape in cross section, as shown more. particularly in Fig. 3,and adjacent each end thereof is provided parallel pins 3 and 4 of likeform projecting transverselyfrom the bottom 1a of angles thereto. Thesepins extend through apertures provided therefor in the body 5 of thetool to engage the respective cone members 6 and 7, the ends of the pinsbeing tapered as at 8 to provide line contact with the respective conemember 5. These cones maybe adjusted as to'distance apart through thecentral adjusting screw 9 which is provided with a head 10 slotted foruse of a screw driver.

By turning the adjusting screw to draw the cones together the faces ofthe abrasive members are moved to a greater radial distance from theaxis of thetool and by the reverse turning of the screw the cones areretracted which is preferably accomplished through use of the springmembers 9a and 10a which engage the lips 2 of each of the holderstending to contract the same. The two cones are yieldingly held apart bya spring 9b surrounding he screw 9 and bearing against the inner ends ofthese cones, as shown in Fig. 1

Subsequent to the formation of the channel member by means of a die asstated, the shouldered pins 3 and 4 have the reduced portions 11 thereofinserted through apertures provided adjacent each end of the shell ormember 1 and the ends thereof peened over to fixedly secure the pins inplace. Upon completion of this step the holder consists of the assembledchanneled member and pins which are maintained in fixed relation withthe shell but it is to be understood that the channel member may beprovided with means for contacting the cones other than what is heretermed pins".

This shell or channeled member 1 further has an aperture in the bottom1a thereof midway between the cone contacting devices indicated at 110.in Fig. 4 and, to secure the stone 12 in place in the holder, I placemold 13 with the longitudinal edges 15a of its side flanges- 1b engaginggage faces 15 thereof, as indicated diagrammatically in Figs. In theform or mold, has previously been positioned the stone 12 which alsolies with its longitudinal outer or working face 12a on a gage'face 14of the form or mold which gage face 14 is exactly parallel with the gagefaces 15 of the form. Due to the two side edges 15a of the finished to adefinite the bottom 1a, the

length from the outer side of parallel with said face'l2a of the stone12 is bottom. In the position of the parts shown in Fig. 4 the stone andthe holder are therefore in a relationship in which they are to be fixedand to fix these parts together I introduce a solder or otherself-hardening material 13a through the aperture 11a. The inaccuraciesin stone thickness shown at 12b in Fig. 5 are thus disposed within 12aof the stone lies par- 15a and bottom of the angle to the axes of theallel with the side edges holder at exactly a right pins 3 and 4.

The assembled abrasive and'holder is then removed from the form and thepins 3 and 4, or

the cone contacting member of whatever form,"

are finished off for contact with the adjusting cones at an exact lengthface of the stone. If pins be utilized for the cone the holder in a formor 4 and .6.

measuring from the is herein shown, and due channeled member beingfinished off parallel with the bottom of the said member against whichthe shoulder of the pins engages, the axes of the pins are therefore, bythis method, exactly at a right angle to the face of the stone. Thisaccuracy in relationship of the stone and holder is necessary in orderto secure precision inoperation of the tool and to function with theadjusting means so that the faces of all the stones cut the same circle.

The object of the invention therefore is secured by this method andcharacter of device, that is, by this form of holder and method ofmaking thereof, precision is attained and a grinding tool is securedthat is accurate in the finishing of a piece of work and accuratepossible adjustments.

I am aware of other-devices of this general character in which abrasivemembers are utilized many of which have stones and holders that arespring projected to working contact with the wall of the aperture beingground. This tool operates differently in that the holders arepositively held in the adjusted position, and while the cone members 6and '7 may traverse or move as a unit longitudinally of the tool bodyand thus permit the abrasive at one end to move toward the axis of thetool and at the other end outwardly therefrom the bit between the pins 6and 7 and the body 5 being sufficiently loose for this purpose, yet asthe tool in its operation is relieved from pressure through the grindingaway of the surface operated on, the adjusting unit including the saidcones takes the neutral position shown in Fig. 1 in which the faces ofthe stones lie ex-. actly parallel with the axis of the tool. Thisposition being assumed at the completion of the grinding operation asthe tool grinds free, the

contacting members, as to the edges 15a of the aperture being groundthrough reciprocation and rotation of the tool therein is of a uniformdiameter throughout its length and with a straight wall. This accuracyin operation is secured by the character of the holder herein disclosedand the absorption of possible inaccuracies by means of a fluid medium131: such as solder, babbitt, lead, varnish, shellac and the like flowedor floated in the space between the holder and the stone.

The combined abrasive provide a unit which may when the'latter is firstput out or to replace worn units of like character'and has been devisedprimarily to avoid inaccuracies resulting from the user of the" toolattempting to replace a worn stone in holders as heretofore utilized inthis art. To secure precision in operation of the tool, the grindingunits should be replaced by new grinding units of thesame accuracy andprecision as the worn grinding units.

By gaging the longitudinal and holder therefor face of the stonethroughout all of its beusedinthetool and the longitudinal edges of thebase or holder in parallelism on the mold the stone and holder may besecured together by self-hardening flowing material in a technicallycorrect position relative to each other and the guide pins and thecooperating parts on the body of the tool regardless of anyirregularities as shown at 12b, in Figs. 5 and 6, onthe back of thestone.

It will be noted that this combined abrasive and: holder permits ofready replacement of simi lar articles used in a cylinder grinder inthat the stone supporting base provides means -for determiningandmaintaining a desired relation of the abrading surface carriedthereby to the 1,920,986 axis of revolution and traverse of the cylindergrinder, and that the grinding stone or abrasive is secured to the baseby a'substantially rigid nel form for use in -tudinal movement ofadherent material which the stone with reference its abrading surface intion, so that on assemblyin the tool the working face ofthe stoneoccupies a technically correct working position.

I claim as my invention:-

1. The hereindescribed method of uniting an abrasive bar and a holderhaving a body of, chana tool which is adapted to grind cylindricalsurfaces by a rotary and longithe tool, and which is promeans fordetermining and permanently positions to the base and with vided withadjusting maintaining a desired relation of the abrading surface carriedthereby to the axis of revolution and traverse of the grinding tool;said method consisting in making said abrasive bar and said holderpositioning said abrasive bar in the channel of said body so that uponassembly in the tool the working face of the bar occupies a technicallycorrect working position; and flowing a liquid adherent material betweensaid holder and bar and permitting said material to harden and rigidlyconnect said holder and bar and maintain the same in said predeterminedrelationship.

2. The herein described method of uniting an abrasive bar and a holdertherefor having a body of channel form and parallel guide pinsprojecting transversely from the outer side of the holder and at rightangles to the length of the same for use in a tool which is adapted togrind cylindrical surfaces by a rotary and longitudinal movement of thetool and which .is provided with adjusting means for determining andmaintaining a desired relation of the abrasive bar to the axis ofrevolution and traverse of the grinding tool; said method consisting inmaking said abrasive bar and holder and pins positioning said body, bar,and pins relatively to one another so that the bar is arranged in thechannel of the body and a space is formed between said determinedposisaid body and bar and said pins are arranged at right angles to theworking face of the bar, whereby upon assembly in the tool the workingface of the bar occupies a technically correct working position relativeto the axis of the tool and said pins properly engage said adjustingmeans; and flowing a self-hardening liquid material in said space so asto rigidly connect said body and bar and maintain them permanently insaid predetermined relationship.

3. The hereindescribed method of uniting an abrasive bar and a holderwhich consists in making said abrasive bar and holder placing saidholder on a gage; placing said bar on a gage and supporting the same ina technically correct position relative to said holder with a spacebetween the bar and holder; and flowing a fluid self-hardening adhesivematerial into the space between said abrasive bar and holder andpermanently securing said abrasive bar to said holder in a position inwhich the face of the abrasive bar occupies tion relatively to otherparts of the tool when assembled therewith.

4. The hereindescrlbed method of uniting an abrasive bar and a holderhaving a body of channeled form and parallel guide pins projecting fromthe back of the body, consisting in making said abrasive bar and holder,placing the abrasive bar in a mold and engaging the face of the abrasivebar with gage faces in the mold, finishing the front edges of thechannel walls so that the same are at right angles to the axes of saidpins, placing said holder in a mold over said abrasive bar and engagingthe front edges of the same with gage faces thereon so that holder andabrasive bar occupy a correct technical posi-- tion relative to oneflowing a fluid self-hardening adherent material between said abrasivebar and body and securing the same together upon hardening saidmaterial.

MARSDEN C. HU'I'IO.

another and said pins; and

